EP1689974A1 - Multi-purpose well bores and method for accessing a subterranean zone from the surface - Google Patents

Multi-purpose well bores and method for accessing a subterranean zone from the surface

Info

Publication number
EP1689974A1
EP1689974A1 EP04819050A EP04819050A EP1689974A1 EP 1689974 A1 EP1689974 A1 EP 1689974A1 EP 04819050 A EP04819050 A EP 04819050A EP 04819050 A EP04819050 A EP 04819050A EP 1689974 A1 EP1689974 A1 EP 1689974A1
Authority
EP
European Patent Office
Prior art keywords
well bore
well
pattern
subterranean
bore
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP04819050A
Other languages
German (de)
French (fr)
Inventor
Steven R. Pauley
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
CDX Gas LLC
Original Assignee
CDX Gas LLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by CDX Gas LLC filed Critical CDX Gas LLC
Publication of EP1689974A1 publication Critical patent/EP1689974A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21BEARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B43/00Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
    • E21B43/30Specific pattern of wells, e.g. optimizing the spacing of wells
    • E21B43/305Specific pattern of wells, e.g. optimizing the spacing of wells comprising at least one inclined or horizontal well
    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21BEARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B43/00Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
    • E21B43/006Production of coal-bed methane

Definitions

  • a set of multi-purpose well bores is provided that each extend from a surface to a subterranean zone, is coupled to a subterranean pattern in the zone formed at least substantially through another one of the multi-purpose well bores, and is used to at least substantially form a subterranean pattern in the zone for another one of the multi-purpose well bores.
  • a well system includes at least two well bores extending from a surface to a subterranean zone. Each of the two well bores is used to form a well bore pattern for the subterranean zone that intersects the other well bore and transports fluid from the subterranean zone to the other well bore for production to the surface.
  • each of the two well bores is used to form a well bore pattern for the subterranean zone that intersects the other well bore and transports fluid from the subterranean zone to the other well bore for production to the surface.
  • 9009877Q.doc Atty. Ref. 17601-039WO1 well bores is operable to collect fluids transported to the well bore by the well bore pattern formed through the other well bore for production to the surface.
  • Technical advantages of one or more embodiments may include providing a well system with two or more multi-purpose well bores. Each multi-purpose well bore may be used to produce gas and other fluids collected by a subterranean pattern that is coupled to the multi-purpose well bore as well to form a disparate subterranean pattern that is coupled to another multi-purpose well bore and has collected fluids produced by the other multi-purpose well bore.
  • a pair of dual purpose well bores are each used to form a substantially horizontal drainage pattern in a subterranean zone for the other dual purpose well bore and to produce gas and other fluids collected by a disparate substantially horizontal drainage pattern connected to the dual purpose well bore.
  • Utilizing the wells for multiple purposes may reduce or limit wells needed for a project and accordingly reduce drilling costs and time. As a result, use of capital per field may be reduced. In addition, an accelerated rate of return may be provided for a given investment in a field.
  • FIGURE 1 illustrates one embodiment of a well system with a first well bore being used to form a subterranean pattern for a second well bore
  • FIGURE 2 illustrates the well system of FIGURE 1 with the first well bore being used to form the subterranean pattern for the second well bore in accordance with another embodiment
  • FIGURE 3 illustrates one embodiment of the well system of FIGURE 1 with the second well bore being used to form a subterranean pattern for the first well bore
  • FIGURES 4A-B illustrate various embodiments of production from the subterranean zone through the first and second well bores of the well system of FIGURE 3;
  • FIGURE 5 illustrates one embodiment of the subterranean patterns of the well system of FIGURE 3;
  • FIGURE 6 illustrates one embodiment of a method for forming a well system with multi-purpose well bores; and
  • FIGURE 7 illustrates another embodiment of the subterranean patterns of the well system of FIGURE 3.
  • DETAILED DESCRIPTION OF THE INVENTION FIGURE 1 illustrates an embodiment of formation of a well system 10 for enhanced access to a subterranean, or subsurface zone, hi this embodiment, the subterranean zone is a coal seam.
  • the subterranean zone may be other suitable types of zones accessed to produce hydrocarbons such as methane gas and other products, to store or process fluids or for other purposes.
  • the subterranean zone may be a shale or other carbonaceous formation.
  • the well system 10 includes a first well bore 12 and a second well bore 32 extending from the surface 14 to a target coal seam 15.
  • the first and second well bores 12 and 32 intersect, penetrate and continue below the coal seam 15.
  • the first and second well bores 12 and 32 may be lined with a suitable well casing 16 that terminates at or above the level of the coal seam 15.
  • the first and second well bores 12 and 32 maybe substantially vertical or non-articulated in that they allow sucker rod, jMoineau and other suitable rod, screw and/or other efficient bore hole pumps or pumping system to lift fluids up the bore to the surface 14.
  • the first and/or second well bores 12 and 32 may include suitable angles to accommodate surface 14 characteristics, geometric characteristics of the coal seam 15, characteristics of intermediate formations and maybe slanted at a suitable angle or angles along their length or parts of their length.
  • the first well and/or second bores 12 and 32 may slant up to 35 degrees along their length or in sections but not themselves be fully articulated to horizontal.
  • the first and second well bores 12 and 32 as well as other well bores may each be substantially uniform in size and shape, differ suitably along their length, be formed in a single drilling operation, or be otherwise suitably formed.
  • the first and second well bores 12 and 32 may be logged either during or after drilling in order to closely approximate and/or locate the exact vertical depth of the coal seam 15. As a result, the coal seam 15 is not missed in subsequent drilling operations. In addition, techniques used to locate the coal seam 15 while drilling may be omitted.
  • the coal seam 15 may be otherwise suitably located.
  • a first cavity 20 is formed in the first well bore 12 in or otherwise proximate to the coal seam 15.
  • a second cavity 34 is formed in the second well bore 32 in or otherwise proximate to the coal seam 15.
  • the cavities 20 and 34 are enlarged areas of the bore holes and may provide a point for intersection of each of the first and second well bores 12 and 32 by distinct articulated well bores used to form an associated well bore pattern in the coal seam 15.
  • the enlarged cavities 20 and 34 may also provide a collection point for fluids drained from the coal seam 15 during production operations and may additionally function as a down hole gas/water separator and/or a surge chamber. In other embodiments, the cavities 20 and 34 may be omitted.
  • the cavities 20 and 34 may have any suitable configuration. In one embodiment, the cavities 20 and 34 each have an enlarged radius of approximately eight feet and a vertical dimension that equals or exceeds the vertical dimension of the coal seam 15.
  • the cavities 20 and 34 may have an enlarged substantially rectangular cross section for intersection by an articulated well bore and a narrow width through which the articulated well bore passes.
  • the cavities 20 and 34 may be formed using suitable under-reaming techniques and equipment such as a dual blade tool using centrifugal force, ratcheting or a piston for actuation, a pantograph and the like.
  • the cavities 20 and 34 may be otherwise formed by suitable tracing and the like.
  • a portion of the first well bore 12 may continue below the cavity 20 to form a sump 22 for the cavity 20.
  • a portion of the second well bore 32 may likewise continue below the cavity 34 to form a sump 36 for the cavity 34.
  • the second well bore 32 is offset a sufficient distance from the first well bore 12 at the surface 14 to permit articulated well bores with large radius curved sections to be drilled between the well bores 12
  • An articulated well bore is any suitable bore extending from a well bore having a first orientation to another substantially disparate orientation or other suitable deviated well bore.
  • the second well bore 32 may be offset a distance of about 300 to about 2000 feet from the first well bore 12. This spacing may reduce or minimizes the angle of the curved portion to reduce friction in each articulated well bore during drilling operations. As a result, reach of the drill string through the articulated well bores 40 is increased and/or maximized.
  • the second well bore 32 may be located otherwise at the surface with respect to the first well bore 12.
  • a first articulated well bore 40 is kicked-off the second well bore 32 above to cavity 34 and/or coal seam 15.
  • a packer or plug 38 may be positioned in the second well bore 12 to prevent drilling fluid and debris from entering the cavity 34.
  • the first articulated well bore 40 is drilled using a drill string 50 that includes a suitable down-hole motor and bit 52.
  • a measurement while drilling (MWD) device 54 may be included in the articulated drill string 50 for controlling the orientation and direction of the well bore drilled by the motor and bit 52.
  • the articulated well bore 40 may be kicked off the second well bore 32 with a whipstock 42, other tool or drilling technique.
  • first well bore 12 and/or cavity 20 may be otherwise positioned relative to the first well bore pattern 60.
  • first well bore 12 and cavity 20 may be positioned toward an end of the well bore pattern 60.
  • pattern 60 may be otherwise suitably formed or connected to the cavity 20.
  • the first pattern 60 is in the coal seam 15 when a majority, substantially all or other substantial portion, is in the seam such that fluids may be transported from or to the seam by the pattern 60.
  • the first well bore pattern 60 may be substantially horizontal corresponding to the geometric characteristics of the coal seam 15.
  • the well bore pattern 60 may include sloped, undulating, or other inclinations of the coal seam 15 or other subterranean zone.
  • gamma ray logging tools and conventional MWD devices may be employed to control and direct the orientation of the drill bit 52 to retain the well bore pattern 60 within the confines of the coal seam 15 and to provide substantially uniform coverage of a desired area within the coal seam 15.
  • the drainage pattern 60 may be an omni-directional well bore pattern operable to intersect a substantial or other suitable number of fractures in the area of the coal seam 15 covered by the pattern 60.
  • the drainage pattern 60 may intersect a significant number of fractures of the coal seam 15 when it intersects a majority of the fractures in the coverage area and plane of the pattern 60.
  • the drainage pattern 60 may intersect a minority percentage of the fractures or a super majority percentage of the fractures in the coverage area and plane of the pattern 60.
  • the coverage area may be the area between the well bores of the pattern 60.
  • the first subterranean pattern 60 may be a pinnate pattern, other suitable multi-lateral or multi-branching pattern, other pattern having a lateral or other network of bores or other patterns of one or more bores with a significant percentage of the total footage of the bores having disparate orientations.
  • the percentage of the bores having disparate orientations is significant when twenty-five to seventy-five percent of the bores have an orientation at least twenty degrees offset from other bores of the pattern, hi a particular embodiment, the well bores of the pattern 60 may have three or more main orientations each including at least 10 percent of the total footage of the bores.
  • the lateral bores may become successively shorter as the pattern progresses out from the cavity or well that is intersected.
  • the distance from the intersected well bore to the distal end of each lateral through the lateral and main bore may be substantially equal.
  • drilling fluid or "mud" may be pumped down the drill string 50 and circulated out of the drill string 50 in the
  • air compressors 62 may be provided at the surface 14 to circulate compressed air down the first well bore 12 and back up through the first articulated well bore 40.
  • the circulated air will admix with the drilling fluids in the annulus around the drill string 50 and create bubbles throughout the column of drilling fluid. This has the effect of lightening the hydrostatic pressure of the drilling fluid and reducing the down-hole pressure sufficiently that drilling conditions do not become over-balanced. Aeration of the drilling fluid reduces down-hole pressure to less than the pressure of the hydrostatic column. For example, in some formations, down-hole pressure may be reduced to approximately 150-200 pounds per square inch (psi). Accordingly, low pressure coal seams and other subterranean resources can be drilled without substantial loss of drilling fluid and contamination of the resource by the drilling fluid.
  • Foam which may be compressed air mixed with water or other suitable fluid, may also be circulated down through the drill string 50 along with the drilling mud in order to aerate the drilling fluid in the annulus as the first articulated well bore 40 is being drilled and, if desired, as the well bore pattern 60 is being drilled.
  • Drilling of the well bore pattern 60 with the use of an air hammer bit or an air-powered down- hole motor will also supply compressed air or foam to the drilling fluid.
  • the compressed air or foam which is used to power the down-hole motor and bit 52 and exits the drill string 50 in the vicinity of the drill bit 52.
  • FIGURE 2 illustrates underbalanced formation of the first articulated well 40 in the well system 10 in accordance with another embodiment. In this embodiment,
  • FIGURE 3 illustrates formation of a second articulated well bore 80 in the well system 10.
  • the second articulated well 80 is formed off of the first well bore 12.
  • Designation of first and second herein are provided for convenience to distinguish between elements of the same or similar type and do not necessarily designate order of formation or association between objects.
  • the second articulated well 80 may be formed immediately after the first well bore 12 is formed, and before formation of the second well bore 32 and the first articulated well 40.
  • the second cavity 34 may be formed through the second articulated well 80 for intersection of the first well bore 32 or the second cavity 34 may be formed in the first well bore 32 to connect already drilled well bores 32 and 80. As previously described, the cavity may be omitted.
  • the drilling rig may again be positioned over the first well bore 12 for formation of the second articulated well bore 80.
  • a packer 38 may be placed in the first well bore 12 between the first cavity 20 and the kick-off point for the second articulated well 80 to prevent cuttings from settling in the cavity 20 and sump 22.
  • a whipstock 42 may be used to kick-off the second articulated well 80.
  • the second articulated well 80 may be substantially similar to the first articulated well 40 and include a curved or radiused portion and a substantially horizontal portion. The substantially horizontal portion, in one embodiment, intersects the second cavity 34 of the second well bore 32. As described in connection with a first articulated well bore 40, the substantially horizontal portion of
  • the second articulated well bore 80 may be formed to any suitable angle relative to the surface 14 and the curved or radiused portion may directly intersect the cavity 34.
  • the curved or radiused portion of the second articulated well bore 80 may in one embodiment have the same or similar radius to that of the first articulated well bore 40.
  • the second articulated well bore 80 may be drilled using the drill string 50 that includes the down-hole motor and bit 52 as well as the MWD device 54 described in connection with formation of the first articulated well bore 40.
  • the second well bore 32 and/or cavity 34 may be otherwise positioned relative to the second well bore pattern 90 and the second articulated well 80.
  • the second well bore pattern 90 may be substantially horizontal corresponding to the geometric characteristics of the coal seam 15.
  • the second well bore pattern 90 may be drilled in and under-balanced or other suitable state as described in connection with the first well bore pattern 60.
  • the second well bore pattern 90 may be a pinnate pattern, other suitable multi-lateral or multi-branching pattern or other pattern having a lateral or other network of bores, or other pattern of one or more bores with a significant percentage of the total footage of the bores having disparate orientations.
  • FIGURES 4A-B illustrate production of gas and other fluids from the coal seam 15 to the surface using the well system 10 in accordance with several embodiments of the present invention.
  • FIGURE 4A illustrates the use of gas lift to produce fluids from the coal seam 15.
  • FIGURE 4B illustrates the use of a rod pump to produce fluids from the coal seam 15.
  • production may be initiated by gas lift to clean out the cavity 20 and kick-off production.
  • the gas lift equipment may be replaced with a rod pump for further removal of fluids during the life of the well.
  • the gas lift system may be replaced with a rod pump for further and/or continued removal of fluids from the cavity 20 over the life of the well, hi these and other embodiments, evolving gas
  • a tubing string 100 may be disposed in each well bore 12 and 32 with a port 102 positioned in the corresponding cavity 20 and 34.
  • Each cavity 20 and 34 provides a reservoir for water or other fluids collected through the corresponding drainage pattern 60 and 90 from the coal seam 15.
  • the tubing string 100 may be a casing string for a rod pump to be installed after the completion of gas lift and the port 102 may be the intake port for the rod pump, hi this embodiment, the tubing may be, for example, a 2 7/8 tubing used for a rod pump. It will be understood that other suitable types of tubing operable to carry air or other gases or materials suitable for gas lift may be used.
  • one or more air compressors 104 are connected to each tubing string 100. Air compressed by the compressors 104 is pumped down each tubing string 100 and exits into the corresponding cavity 20 and 34 at the port 102.
  • the air used for gas lift and/or for the previously described under balanced drilling may be ambient air at the site or may be or include any other suitable gas.
  • produced gas may be returned to the cavity and used for gas lift, hi the cavities 20 and 34, the compressed air expands and suspends liquid droplets within its volume and lifts them to the surface.
  • air may be compressed to three hundred to three hundred fifty psi and provided at a rate of nine hundred cubic feet per minute (CFM).
  • CFM cubic feet per minute
  • the gas lift system may lift up to three 1 thousand, four thousand or five thousand barrels a day of water to the surface.
  • air and fluids from each well bore 12 and 32 are fed into a fluid separator 106.
  • Produced gas and lift air may be outlet at air/gas ports 108 and flared while remaining fluids are outlet at fluid ports 110 for transport or other removal, reinjection or surface runoff. It will be understood that water may be otherwise suitably removed from the cavities 20 and 34 and/or patterns 60 and 90 without production to the surface 14. For example, the water maybe reinjected into an
  • the rate and/or pressure of compressed air provided to the cavities 20 and 34 may be adjusted to control the volume of water produced to the surface.
  • a sufficient rate and/or pressure of compressed air may be provided to the cavities 20 and 34 to lift all or substantially all of the water collected by the cavities from a coal seam 15.
  • the rate and/or pressure of air provided may be controlled to limit water production below the attainable amount due to limitations in disposing of produced water and/or damage to the coal seam 15 or equipment by high rates of production.
  • a turbidity meter may be used at the well head to monitor the presence of particles in the produced water. If the amount of particles is over a specified limit, a controller may adjust a flow control valve to reduce the production rate.
  • the controller may adjust the valve to specific flow rates and/or use feedback from the turbidity meter to adjust the flow control valve to a point where the amount of particles in the water is at a specified amount.
  • a pumping unit 120 is provided for each of the first and second well bores 12 and 32 and extends to the corresponding cavity 20 and 34.
  • the cavities 20 and 34 provide a reservoir for accumulated fluids that may act as a surge tank and that may allow intermittent pumping without adverse effects of a hydrostatic head caused by accumulated fluids in the well bores 12 and 32. As a result, a large volume of fluids may be collected in the cavities 20 and 34 without any pressure or any substantial pressure being exerted on the formation from the collected fluids.
  • the pumping units 120 include an inlet port 122 in each cavity 20 and 34 and may comprise a tubing string 124 with sucker rods 126 extending through the tubing string 124.
  • Each inlet 122 may be positioned at or just above a center height of the
  • the inlet 122 may be suitably angled with or within the cavity.
  • the sucker rods 126 are reciprocated by a suitable surface mounted apparatus, such as a powered walking beam 128 to operate the pumping unit 120.
  • the pumping unit 120 may comprise a Moineau or other suitable pump operable to lift fluids vertically or substantially vertically. The pumping units 120 are used to remove water and entrained coal fines from the coal seam 15 via the well bore patterns 60 and 90.
  • coal seam gas may flow from the coal seam 15 to the surface 14 through the annulus of the first and second well bores 12 and 32 around the tubing strings and be removed via piping attached to a wellhead apparatus.
  • the pumping unit 120 may be operated continuously or as needed to remove water drained from the coal seam 15 into the enlarged cavities 20 and 34.
  • gas lift is continued until the wells are kicked-off to a self- sustaining flow at which time the wells are briefly shut-in to allow replacement of the gas lift equipment with the fluid pumping equipment.
  • the wells are then allowed to flow in self-sustaining flow subject to periodic periods of being shut-in for maintenance, lack of demand for gas and the like.
  • a well may need to be pumped for a few cycles, a few hours, days or weeks, to again initiate self- sustaining flow or other suitable production rate of gas.
  • the rod pumps may each produce approximately eight gallons per minute of water from a corresponding cavity 20 or 34 to the surface.
  • a well is at self sustaining flow when the flow of gas is operable to lift any produced water such that the well may operate for an extended period of six weeks or more without pumping or artificial gas lift.
  • the well may require periodic pumping between periods of self sustaining flow.
  • FIGURE 5 illustrates one embodiment of the subterranean patterns 60 and 90 for accessing the coal seam 15 or other subterranean zone.
  • the patterns 60 and 90 may be used to remove or inject water, gas or other fluids.
  • the subterranean patterns 60 and 90 each comprises a multi-lateral pattern that has a main bore with generally symmetrically arranged and appropriately spaced laterals extending from each side of the main bore.
  • the term each means every one of at least a subset of the identified items. It will be understood that other suitable multi-branching or other patterns including or connected to a surface production bore may be used.
  • the patterns 60 and 90 may each comprise a single main bore.
  • patterns 60 and 90 each include a main bore 150 extending from a corresponding cavity 20 or 34, or intersecting well bore 12 or 32, along a center of a coverage area to a distal end of the coverage area.
  • the main bore 150 includes one or more primary lateral bores 152 extending from the main bore 150 to or at least approximately to the periphery of the coverage area.
  • the primary lateral bores 152 may extend from opposite sides of the main bore 150.
  • the primary lateral bores 152 may mirror each other on opposite sides of the main bore 150 or may be offset from each other along the main bore 150.
  • Each of the primary lateral bores 152 may include a radius curving portion extending from the main bore 150 and a straight portion formed after the curved portion has reached a desired orientation.
  • the primary lateral bores 152 may be substantially evenly spaced on each side of the main bore 150 and extend from the main bore 150 at an angle of approximately 45 degrees.
  • the primary lateral bores 152 may shorten in length based on progression away from the corresponding cavity 20 or 34. Accordingly the distance between the cavity or intersecting well bore and the distal end of each primary lateral bore 152 through the pattern may be substantially equal for each primary lateral 152.
  • One or more secondary lateral bores 154 may be formed off one or more of the primary lateral bores 152.
  • a set of secondary laterals 154 may be formed off the first primary lateral bores 152 of each pattern 60 and 90 closest to the corresponding cavity 20 and 34.
  • the secondary laterals 154 may provide coverage in the area between the primary lateral bores 152 of patterns 60 and
  • a first primary lateral 154 may include a reversed radius section to provide more uniform coverage of the coal seam 15.
  • the subterranean patterns 60 and 90 with their central bore and generally symmetrically arranged and appropriately spaced auxiliary bores on each side may provide a substantially uniform pattern for draining fluids from a coal seam 15 or other subterranean formation.
  • the number and spacing of the lateral bores maybe adjusted depending on the absolute, relative and/or effective permeability of the coal seam and the size of the area covered by the pattern.
  • the area covered by the pattern may be the area drained by the pattern, the area of a spacing unit that the pattern is designed to drain, the area within the distal points or periphery of the pattern and/or the area within the periphery of the pattern as well as the surrounding area out to a periphery intermediate to adjacent or neighboring patterns.
  • the coverage area may also include the depth, or thickness of the coal seam or, for thick coal seams, a portion of the thickness of the seam.
  • the pattern may include upward or downward extending branches in addition to horizontal branches.
  • the coverage area may be a square, other quadrilateral, or other polygon, circular, oval or other ellipsoid or grid area and may be nested with other patterns of the same or similar type.
  • the well bore 150 and the lateral bores 152 and 154 of patterns 60 and 90 are formed by drilling through the corresponding cavity 20 or 34 using the drill string 50 and an appropriate drilling apparatus. During this operation, gamma ray logging tools and conventional MWD technologies may be employed to control the direction and orientation of the drill bit 52 so as to retain the well bore pattern within the confines of the coal seam 15 and to maintain proper spacing and orientation of the well bores 150 and 152.
  • the main well bore 150 of each pattern 60 and 90 is drilled with an incline at each of a plurality of lateral branch points 156.
  • the drill string 50 is backed up to each successive lateral point 156 from which a primary lateral bore 152 is drilled on each side of the well bore 150.
  • the secondary laterals 154 may be similarly formed. It will be understood that the subterranean patterns 60 and 90 may be otherwise suitably formed.
  • FIGURE 6 is a flow diagram illustrating a method for surface production of gas from a subterranean zone in accordance with one embodiment.
  • the subterranean zone is a coal seam and well system 10 with a pair of cavities is used to produce gas from the coal seam.
  • the subterranean zone may comprise gas bearing shales and other suitable formations and that the well system 10 may have any suitable number of multi-purpose wells used to produce gas to the surface and to form bores for another producing well.
  • the method begins after the region to be drained and the type of subterranean patterns for the region have been determined.
  • any suitable pinnate, other substantially uniform pattern providing less than ten or even five percent trapped zones in the coverage area, omni-directional or multi-branching pattern may be used to provide coverage for the region.
  • a first substantially vertical or other suitable well 12 is drilled from the surface 14 through the coal seam 15.
  • Slant and other suitable well configurations may, for example, instead be used.
  • the drainage patterns may be formed off of a slant well or a slanting portion of a well with a vertical or other section at the surface.
  • down hole logging equipment is utilized to exactly identify the location of the coal seam 15 in the first well bore 12.
  • the first enlarged diameter or other cavity 20 is formed in the first well bore 12 at the location of the coal seam 15.
  • the first cavity 20 may be formed by underreaming and other suitable techniques.
  • the cavity may be formed by tracing.
  • the second substantially vertical or other suitable well 32 is drilled from the surface 14 through the coal seam 15. Slant or other suitable well configurations may instead be used.
  • down-hole logging equipment is utilized to exactly identify the location of the coal seam 15 in the second well bore 32.
  • the second enlarged diameter or other cavity 34 is formed in the second well bore 32 at the location of the coal seam 15.
  • the second cavity 34 may be formed by any other suitable technique.
  • the first articulated well bore 40 is drilled off the second well bore 32 to intersect the enlarged diameter cavity 20 of the first well bore 12.
  • the main well bore 150 for the first subterranean pattern 60 is drilled through the first articulated well bore 40 into the coal seam 15.
  • lateral kick-off points, or bumps may be formed along the main bore 150 during its formation to facilitate drilling of the lateral bores 152 and 154.
  • lateral bores 152 and 154 for the subterranean pattern are drilled at step 216.
  • the second articulated well bore 80 is drilled off the first well bore 12 to intersect the large diameter cavity 32 of the second well bore 32.
  • the main well bore 150 for the second subterranean pattern 90 is drilled through the second articulated well bore 80 into the coal seam 15.
  • lateral kick-off points or bumps may be formed along the main bore 150 in its formation to facilitate drilling of the lateral bores 152 and 154.
  • lateral bores 152 and 154 for the second pattern 90 are formed.
  • gas lift equipment is installed in each of the first and second well bores 12 and 32 in preparation for blow-down of the bores.
  • compressed air is pumped down the substantially vertical well bores 12 and 32 to provide blow- down.
  • the compressed air expands in the cavities 20 and 34, suspends the collected fluids within its volume and lifts the fluid to the surface.
  • air and produced methane or other gases are separated from the water and flared.
  • the water may be disposed of as runoff, reinjected or moved to a remote site for disposal.
  • the blow-down may clean the cavities 20 and 34 and the vertical well bores 12 and 34 of debris and kick-off the well to initiate self-sustaining flow. In a particular embodiment, the blow-down may last for one, two or a few weeks.
  • production equipment is installed in the substantially vertical well bores 12 and 34 in place of the gas lift equipment.
  • the production equipment may include a well head and a sucker rod pump extending down into the cavities 20 and 34 for removing water from the coal seam 15. If a well is shut in for any period of time, water builds up in the cavity 20 or 34 or self-sustaining flow is otherwise terminated,
  • the pump may be used to remove water and drop the pressure in the coal seam 15 to allow methane gas to continue to be diffused and to be produced up the annulus of the substantially vertical well bore.
  • methane gas diffused from the coal seam 15 is continuously produced at the surface 14.
  • Methane gas may be produced in two-phase flow with the water or otherwise produced with water and/or produced after reservoir pressure has been suitably reduced.
  • water that drains through the drainage patterns into the cavities that is not lifted by the produced gas is pumped to the surface with the rod pumping unit. Water may be continuously or intermittently pumped as needed for removal from the cavities 20 and 34.
  • decisional step 234 it is determined whether the production of gas from the coal seam 15 is complete. In a particular embodiment, approximately seventy-five percent of the total gas in the coverage area of the coal seam may be produced at the completion of gas production. The production of gas may be complete after the cost of the collecting the gas exceeds the revenue generated by the well. Alternatively, gas may continue to be produced from the well until a remaining level of gas in the coal seam 15 is below required levels for mining or other operations. If production of the gas is not complete, the No branch of decisional step 234 returns to steps 230 and 232 in which gas and/or water continue to be removed from the coal seam 15. Upon completion of production, the Yes branch of decisional step 234 leads to the end of the process by which gas is produced from a coal seam.
  • FIGURE 7 illustrates another embodiment of the subterranean patterns 60 and 90 for accessing the coal seam 15 or other subterranean zone.
  • the subterranean patterns 60 and 90 may each comprise a multi-lateral pattern that has a main bore with generally symmetrically arranged and appropriately spaced laterals extending from each side of the main bore.
  • the patterns 60 and 90 are each formed with laterals extending from the main bore before and after interception of the corresponding cavity 20 or 34.
  • patterns 60 and 90 may each include a main bore 250 extending through a corresponding cavity 20 or 34, or intersecting well bore 12 or 32, along a center of a coverage area.
  • the main bore 250 includes one or more primary lateral bores 252 extending from the main bore 250 to or at least approximately to the periphery of the coverage area.
  • the primary lateral bores 252 may extend from opposite sides of the main bore 250.
  • One or more secondary lateral bores 254 may be formed off one or more of the primary lateral bores 252.
  • a set of secondary lateral bores 254 may be formed off the first primary lateral bore 252 of each pattern 60 and 90.
  • the patterns 60 and 90 may be formed with the cavities 20 and 34 between laterals 252 to achieve a desired spacing.
  • the wells 12 and 32, and thus cavities 20 and 34 may be vertical and offset a minimum well statutory spacing by forming laterals 252 and 254 between the cavities 20 and 34.
  • spacing requirements may be met and/or special exemptions or permission requests avoided while still providing access to the coverage area.

Abstract

A well system (10) includes at least two well bores (12, 32) extending from a surface (14) to a subterranean zone (15). Each of the two well bores (12, 32) is used to form a well bore pattern (60, 90) for the subterranean zone (15) that intersects the other well bore (12, 32) and transports fluid from the subterranean zone (15) to the other well bore (12, 32) for production to the surface. In addition, each of the two well bores (12, 32) is operable to collect fluids transported to the well bore (12, 32) by the well bore pattern (60, 90) formed through the other well bore (12, 32) for production to the surface (14).

Description

Atty. Ref. 17601-039WO1 MULTI-PURPOSE WELL BORES AMD METHOD FOR ACCESSING A SUBTERRANEAN ZONE FROM THE SURFACE
REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Patent Application No. 10/715,300 filed November 17, 2003 entitled "Multi-Purpose Well Bores and Method for Accessing a Subterranean Zone from the Surface". TECHNICAL FIELD OF THE INVENTION Present invention relates generally to accessing a subterranean zone from the surface for production and/or injection of gas or other fluids, and more particularly to multi-purpose well bores and method for accessing a subterranean zone from the surface. BACKGROUND OF THE INVENTION Subterranean deposits of coal, shale and other formations often contain substantial quantities of methane gas. Vertical wells and vertical well patterns have been used to access coal and shale formations to produce the methane gas. More recently, horizontal patterns and interconnected well bores have also been used to produce methane gas from coal and shale formations and/or to sequester carbon dioxide. SUMMARY OF THE INVENTION Multi-purpose well bores and method for accessing a subterranean zone from the surface are provided. In a particular embodiment, a set of multi-purpose well bores is provided that each extend from a surface to a subterranean zone, is coupled to a subterranean pattern in the zone formed at least substantially through another one of the multi-purpose well bores, and is used to at least substantially form a subterranean pattern in the zone for another one of the multi-purpose well bores. In accordance with one embodiment of the present invention, a well system includes at least two well bores extending from a surface to a subterranean zone. Each of the two well bores is used to form a well bore pattern for the subterranean zone that intersects the other well bore and transports fluid from the subterranean zone to the other well bore for production to the surface. In addition, each of the two
9009877Q.doc Atty. Ref. 17601-039WO1 well bores is operable to collect fluids transported to the well bore by the well bore pattern formed through the other well bore for production to the surface. Technical advantages of one or more embodiments may include providing a well system with two or more multi-purpose well bores. Each multi-purpose well bore may be used to produce gas and other fluids collected by a subterranean pattern that is coupled to the multi-purpose well bore as well to form a disparate subterranean pattern that is coupled to another multi-purpose well bore and has collected fluids produced by the other multi-purpose well bore. In a particular embodiment, a pair of dual purpose well bores are each used to form a substantially horizontal drainage pattern in a subterranean zone for the other dual purpose well bore and to produce gas and other fluids collected by a disparate substantially horizontal drainage pattern connected to the dual purpose well bore. Utilizing the wells for multiple purposes may reduce or limit wells needed for a project and accordingly reduce drilling costs and time. As a result, use of capital per field may be reduced. In addition, an accelerated rate of return may be provided for a given investment in a field. The above and elsewhere describe technical advantages may be provided and/or evidenced by some, all or none of the various embodiments. In addition, other technical advantages may be readily apparent from the following figures, descriptions, and claims. BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 illustrates one embodiment of a well system with a first well bore being used to form a subterranean pattern for a second well bore; FIGURE 2 illustrates the well system of FIGURE 1 with the first well bore being used to form the subterranean pattern for the second well bore in accordance with another embodiment; FIGURE 3 illustrates one embodiment of the well system of FIGURE 1 with the second well bore being used to form a subterranean pattern for the first well bore; FIGURES 4A-B illustrate various embodiments of production from the subterranean zone through the first and second well bores of the well system of FIGURE 3;
90098770.doc Atty. Ref. 17601-039WO1 FIGURE 5 illustrates one embodiment of the subterranean patterns of the well system of FIGURE 3; FIGURE 6 illustrates one embodiment of a method for forming a well system with multi-purpose well bores; and FIGURE 7 illustrates another embodiment of the subterranean patterns of the well system of FIGURE 3. DETAILED DESCRIPTION OF THE INVENTION FIGURE 1 illustrates an embodiment of formation of a well system 10 for enhanced access to a subterranean, or subsurface zone, hi this embodiment, the subterranean zone is a coal seam. The subterranean zone may be other suitable types of zones accessed to produce hydrocarbons such as methane gas and other products, to store or process fluids or for other purposes. For example, the subterranean zone may be a shale or other carbonaceous formation. Referring to FIGURE 1, the well system 10 includes a first well bore 12 and a second well bore 32 extending from the surface 14 to a target coal seam 15. The first and second well bores 12 and 32 intersect, penetrate and continue below the coal seam 15. The first and second well bores 12 and 32 may be lined with a suitable well casing 16 that terminates at or above the level of the coal seam 15. The first and second well bores 12 and 32 maybe substantially vertical or non-articulated in that they allow sucker rod, jMoineau and other suitable rod, screw and/or other efficient bore hole pumps or pumping system to lift fluids up the bore to the surface 14. Thus, the first and/or second well bores 12 and 32 may include suitable angles to accommodate surface 14 characteristics, geometric characteristics of the coal seam 15, characteristics of intermediate formations and maybe slanted at a suitable angle or angles along their length or parts of their length. In particular embodiments, the first well and/or second bores 12 and 32 may slant up to 35 degrees along their length or in sections but not themselves be fully articulated to horizontal. The first and second well bores 12 and 32 as well as other well bores may each be substantially uniform in size and shape, differ suitably along their length, be formed in a single drilling operation, or be otherwise suitably formed.
90Q98770.doc Atty. Ref. 17601-039WO1 The first and second well bores 12 and 32 may be logged either during or after drilling in order to closely approximate and/or locate the exact vertical depth of the coal seam 15. As a result, the coal seam 15 is not missed in subsequent drilling operations. In addition, techniques used to locate the coal seam 15 while drilling may be omitted. The coal seam 15 may be otherwise suitably located. A first cavity 20 is formed in the first well bore 12 in or otherwise proximate to the coal seam 15. A second cavity 34 is formed in the second well bore 32 in or otherwise proximate to the coal seam 15. As described in more detail below, the cavities 20 and 34 are enlarged areas of the bore holes and may provide a point for intersection of each of the first and second well bores 12 and 32 by distinct articulated well bores used to form an associated well bore pattern in the coal seam 15. The enlarged cavities 20 and 34 may also provide a collection point for fluids drained from the coal seam 15 during production operations and may additionally function as a down hole gas/water separator and/or a surge chamber. In other embodiments, the cavities 20 and 34 may be omitted. The cavities 20 and 34 may have any suitable configuration. In one embodiment, the cavities 20 and 34 each have an enlarged radius of approximately eight feet and a vertical dimension that equals or exceeds the vertical dimension of the coal seam 15. In another embodiment, the cavities 20 and 34 may have an enlarged substantially rectangular cross section for intersection by an articulated well bore and a narrow width through which the articulated well bore passes. In these embodiments, the cavities 20 and 34 may be formed using suitable under-reaming techniques and equipment such as a dual blade tool using centrifugal force, ratcheting or a piston for actuation, a pantograph and the like. The cavities 20 and 34 may be otherwise formed by suitable tracing and the like. A portion of the first well bore 12 may continue below the cavity 20 to form a sump 22 for the cavity 20. A portion of the second well bore 32 may likewise continue below the cavity 34 to form a sump 36 for the cavity 34. In the embodiment illustrated in FIGURE 1, the second well bore 32 is offset a sufficient distance from the first well bore 12 at the surface 14 to permit articulated well bores with large radius curved sections to be drilled between the well bores 12
90098770.doc 4 Atty. Ref. 17601-039WO1 and 32. An articulated well bore is any suitable bore extending from a well bore having a first orientation to another substantially disparate orientation or other suitable deviated well bore. To provide the curved portion with a radius of 100-800 feet, the second well bore 32 may be offset a distance of about 300 to about 2000 feet from the first well bore 12. This spacing may reduce or minimizes the angle of the curved portion to reduce friction in each articulated well bore during drilling operations. As a result, reach of the drill string through the articulated well bores 40 is increased and/or maximized. In another embodiments, the second well bore 32 may be located otherwise at the surface with respect to the first well bore 12. A first articulated well bore 40 is kicked-off the second well bore 32 above to cavity 34 and/or coal seam 15. A packer or plug 38 may be positioned in the second well bore 12 to prevent drilling fluid and debris from entering the cavity 34. hi one embodiment, the first articulated well bore 40 is drilled using a drill string 50 that includes a suitable down-hole motor and bit 52. A measurement while drilling (MWD) device 54 may be included in the articulated drill string 50 for controlling the orientation and direction of the well bore drilled by the motor and bit 52. The articulated well bore 40 may be kicked off the second well bore 32 with a whipstock 42, other tool or drilling technique. After the first cavity 20 of the first well bore 12 has been intersected by the first articulated well bore 40, drilling of the articulated well bore 40 is continued through the cavity 20 with drill string 50 to provide a first subterranean well bore pattern 60 in the coal seam 15 that is connected or otherwise coupled to the first well bore 12. hi other embodiments, the first well bore 12 and/or cavity 20 may be otherwise positioned relative to the first well bore pattern 60. For example, in one embodiment, the first well bore 12 and cavity 20 may be positioned toward an end of the well bore pattern 60. Thus, the first well bore 12 and/or cavity 20 may be positioned within the pattern 60 at or between sets of laterals. Also, pattern 60 may be otherwise suitably formed or connected to the cavity 20. The first pattern 60 is in the coal seam 15 when a majority, substantially all or other substantial portion, is in the seam such that fluids may be transported from or to the seam by the pattern 60.
90098770.doc Atty. Ref. 17601-039WO1 The first well bore pattern 60 may be substantially horizontal corresponding to the geometric characteristics of the coal seam 15. The well bore pattern 60 may include sloped, undulating, or other inclinations of the coal seam 15 or other subterranean zone. During formation of the well bore pattern 60, gamma ray logging tools and conventional MWD devices may be employed to control and direct the orientation of the drill bit 52 to retain the well bore pattern 60 within the confines of the coal seam 15 and to provide substantially uniform coverage of a desired area within the coal seam 15. In one embodiment, as described in more detail below, the drainage pattern 60 may be an omni-directional well bore pattern operable to intersect a substantial or other suitable number of fractures in the area of the coal seam 15 covered by the pattern 60. The drainage pattern 60 may intersect a significant number of fractures of the coal seam 15 when it intersects a majority of the fractures in the coverage area and plane of the pattern 60. In other embodiments, the drainage pattern 60 may intersect a minority percentage of the fractures or a super majority percentage of the fractures in the coverage area and plane of the pattern 60. The coverage area may be the area between the well bores of the pattern 60. The first subterranean pattern 60 may be a pinnate pattern, other suitable multi-lateral or multi-branching pattern, other pattern having a lateral or other network of bores or other patterns of one or more bores with a significant percentage of the total footage of the bores having disparate orientations. The percentage of the bores having disparate orientations is significant when twenty-five to seventy-five percent of the bores have an orientation at least twenty degrees offset from other bores of the pattern, hi a particular embodiment, the well bores of the pattern 60 may have three or more main orientations each including at least 10 percent of the total footage of the bores. For a pinnate pattern, the lateral bores may become successively shorter as the pattern progresses out from the cavity or well that is intersected. In addition, the distance from the intersected well bore to the distal end of each lateral through the lateral and main bore may be substantially equal. During the process of drilling the well bore pattern 60, drilling fluid or "mud" may be pumped down the drill string 50 and circulated out of the drill string 50 in the
90098770.doc 6 Atty. Ref. 17601-039WO1 vicinity of the bit 52, where it is used to scour the formation and to remove formation cuttings. The cuttings are then entrained in the drilling fluid which circulates up through the annulus between the drill string 50 and the walls of first articulated well bore 40 and the second well bore 32 until it reaches the surface 14, where the cuttings are removed from the drilling fluid and the fluid is then recirculated. To prevent overbalance drilling conditions during formation of the well bore pattern 60, air compressors 62 may be provided at the surface 14 to circulate compressed air down the first well bore 12 and back up through the first articulated well bore 40. The circulated air will admix with the drilling fluids in the annulus around the drill string 50 and create bubbles throughout the column of drilling fluid. This has the effect of lightening the hydrostatic pressure of the drilling fluid and reducing the down-hole pressure sufficiently that drilling conditions do not become over-balanced. Aeration of the drilling fluid reduces down-hole pressure to less than the pressure of the hydrostatic column. For example, in some formations, down-hole pressure may be reduced to approximately 150-200 pounds per square inch (psi). Accordingly, low pressure coal seams and other subterranean resources can be drilled without substantial loss of drilling fluid and contamination of the resource by the drilling fluid. Foam, which may be compressed air mixed with water or other suitable fluid, may also be circulated down through the drill string 50 along with the drilling mud in order to aerate the drilling fluid in the annulus as the first articulated well bore 40 is being drilled and, if desired, as the well bore pattern 60 is being drilled. Drilling of the well bore pattern 60 with the use of an air hammer bit or an air-powered down- hole motor will also supply compressed air or foam to the drilling fluid. In this case, the compressed air or foam which is used to power the down-hole motor and bit 52 and exits the drill string 50 in the vicinity of the drill bit 52. However, the larger volume of air which can be circulated down the first well bore 12 permits greater aeration of the drilling fluid than generally is possible by air supplied through the drill string 50. FIGURE 2 illustrates underbalanced formation of the first articulated well 40 in the well system 10 in accordance with another embodiment. In this embodiment,
90098770.doc 7 Atty. Ref. 17601-039WO1 after intersection of the cavity 20 by the first articulated well bore 40, a Moineau or other suitable pump 64 is installed in the cavity 20 to pump drilling fluid and cuttings to the surface 14 through the first well bore 12. This eliminates or reduces both the head pressure and the friction of air and fluid returning up the first articulated well bore 40 and reduces down-hole pressure to nearly zero. Accordingly, coal seams 15 and other subterranean resources having ultra low pressures below 150 psi can be accessed from the surface 14. Additionally, the risk of combining air and methane in the well may be eliminated or reduced. FIGURE 3 illustrates formation of a second articulated well bore 80 in the well system 10. In the illustrated embodiment, the second articulated well 80 is formed off of the first well bore 12. Designation of first and second herein are provided for convenience to distinguish between elements of the same or similar type and do not necessarily designate order of formation or association between objects. Thus, for example, the second articulated well 80 may be formed immediately after the first well bore 12 is formed, and before formation of the second well bore 32 and the first articulated well 40. In such an embodiment, the second cavity 34 may be formed through the second articulated well 80 for intersection of the first well bore 32 or the second cavity 34 may be formed in the first well bore 32 to connect already drilled well bores 32 and 80. As previously described, the cavity may be omitted. Referring to FIGURE 3, after formation of the first articulated well 40 and associated first subterranean pattern 60 are completed, the drilling rig may again be positioned over the first well bore 12 for formation of the second articulated well bore 80. A packer 38 may be placed in the first well bore 12 between the first cavity 20 and the kick-off point for the second articulated well 80 to prevent cuttings from settling in the cavity 20 and sump 22. A whipstock 42 may be used to kick-off the second articulated well 80. The second articulated well 80 may be substantially similar to the first articulated well 40 and include a curved or radiused portion and a substantially horizontal portion. The substantially horizontal portion, in one embodiment, intersects the second cavity 34 of the second well bore 32. As described in connection with a first articulated well bore 40, the substantially horizontal portion of
90098770.doc ' 8 Atty. Ref. 17601-039WO1 the second articulated well bore 80 may be formed to any suitable angle relative to the surface 14 and the curved or radiused portion may directly intersect the cavity 34. The curved or radiused portion of the second articulated well bore 80 may in one embodiment have the same or similar radius to that of the first articulated well bore 40. The second articulated well bore 80 may be drilled using the drill string 50 that includes the down-hole motor and bit 52 as well as the MWD device 54 described in connection with formation of the first articulated well bore 40. After the second cavity 34 of the second well bore 32 has been intersected by the second articulated well bore 80, drilling is continued through the cavity 32 with the drill string 50 to provide a second subterranean well bore pattern 90 in the coal seam 15. In other embodiments, the second well bore 32 and/or cavity 34 may be otherwise positioned relative to the second well bore pattern 90 and the second articulated well 80. The second well bore pattern 90 may be substantially horizontal corresponding to the geometric characteristics of the coal seam 15. The second well bore pattern 90 may be drilled in and under-balanced or other suitable state as described in connection with the first well bore pattern 60. The second well bore pattern 90 may be a pinnate pattern, other suitable multi-lateral or multi-branching pattern or other pattern having a lateral or other network of bores, or other pattern of one or more bores with a significant percentage of the total footage of the bores having disparate orientations. FIGURES 4A-B illustrate production of gas and other fluids from the coal seam 15 to the surface using the well system 10 in accordance with several embodiments of the present invention. In particular, FIGURE 4A illustrates the use of gas lift to produce fluids from the coal seam 15. FIGURE 4B illustrates the use of a rod pump to produce fluids from the coal seam 15. In one embodiment, production may be initiated by gas lift to clean out the cavity 20 and kick-off production. After production kick-off, the gas lift equipment may be replaced with a rod pump for further removal of fluids during the life of the well. Thus, while gas lift may be used to produce fluids during the life of the well, for economic reasons, the gas lift system may be replaced with a rod pump for further and/or continued removal of fluids from the cavity 20 over the life of the well, hi these and other embodiments, evolving gas
9Q098770.doc 9 Atty. Ref. 17601-039WO1 disorbed from coal in the seam 15 and produced to the surface 14 is collected at the well head and after fluid separation may be flared, stored or fed into a pipeline. Referring to FIGURE 4 A, after the first and second well bores 12 and 32, and the first and second well bore pattern 60 and 90 have been drilled, a tubing string 100 may be disposed in each well bore 12 and 32 with a port 102 positioned in the corresponding cavity 20 and 34. Each cavity 20 and 34 provides a reservoir for water or other fluids collected through the corresponding drainage pattern 60 and 90 from the coal seam 15. In one embodiment, the tubing string 100 may be a casing string for a rod pump to be installed after the completion of gas lift and the port 102 may be the intake port for the rod pump, hi this embodiment, the tubing may be, for example, a 2 7/8 tubing used for a rod pump. It will be understood that other suitable types of tubing operable to carry air or other gases or materials suitable for gas lift may be used. At the surface 14, one or more air compressors 104 are connected to each tubing string 100. Air compressed by the compressors 104 is pumped down each tubing string 100 and exits into the corresponding cavity 20 and 34 at the port 102. The air used for gas lift and/or for the previously described under balanced drilling may be ambient air at the site or may be or include any other suitable gas. For example, produced gas may be returned to the cavity and used for gas lift, hi the cavities 20 and 34, the compressed air expands and suspends liquid droplets within its volume and lifts them to the surface. In one embodiment, for shallow coal beds 15 at or around one thousand feet, air may be compressed to three hundred to three hundred fifty psi and provided at a rate of nine hundred cubic feet per minute (CFM). At this rate and pressure, the gas lift system may lift up to three1 thousand, four thousand or five thousand barrels a day of water to the surface. At the surface, air and fluids from each well bore 12 and 32 are fed into a fluid separator 106. Produced gas and lift air may be outlet at air/gas ports 108 and flared while remaining fluids are outlet at fluid ports 110 for transport or other removal, reinjection or surface runoff. It will be understood that water may be otherwise suitably removed from the cavities 20 and 34 and/or patterns 60 and 90 without production to the surface 14. For example, the water maybe reinjected into an
9Q098770.doc Atty. Ref. 17601-039WO1 adjacent or other underground structure by pumping, directing or allowing the flow of the water to the other structure. During gas lift, the rate and/or pressure of compressed air provided to the cavities 20 and 34 may be adjusted to control the volume of water produced to the surface. In one embodiment, a sufficient rate and/or pressure of compressed air may be provided to the cavities 20 and 34 to lift all or substantially all of the water collected by the cavities from a coal seam 15. This may provide for a rapid pressure drop in the coverage area of the coal seam 15 and allow for kick-off of the wells 12 and 34 to self-sustaining flow within one, two or a few weeks, hi other embodiments, the rate and/or pressure of air provided may be controlled to limit water production below the attainable amount due to limitations in disposing of produced water and/or damage to the coal seam 15 or equipment by high rates of production. In a particular embodiment, a turbidity meter may be used at the well head to monitor the presence of particles in the produced water. If the amount of particles is over a specified limit, a controller may adjust a flow control valve to reduce the production rate. The controller may adjust the valve to specific flow rates and/or use feedback from the turbidity meter to adjust the flow control valve to a point where the amount of particles in the water is at a specified amount. Referring to FIGURE 4B, a pumping unit 120 is provided for each of the first and second well bores 12 and 32 and extends to the corresponding cavity 20 and 34. The cavities 20 and 34 provide a reservoir for accumulated fluids that may act as a surge tank and that may allow intermittent pumping without adverse effects of a hydrostatic head caused by accumulated fluids in the well bores 12 and 32. As a result, a large volume of fluids may be collected in the cavities 20 and 34 without any pressure or any substantial pressure being exerted on the formation from the collected fluids. Thus, even during non-extended periods of non-pumping, water and/or gas may continue to flow from the well bore patterns 60 and 90 and accumulate in the cavities 20 and 34. The pumping units 120 include an inlet port 122 in each cavity 20 and 34 and may comprise a tubing string 124 with sucker rods 126 extending through the tubing string 124. Each inlet 122 may be positioned at or just above a center height of the
9Q09877Q.doc Atty. Ref. 17601-039WO1 corresponding cavity 20 or 34 to avoid gas lock and to avoid debris that collects in the sump. The inlet 122 may be suitably angled with or within the cavity. The sucker rods 126 are reciprocated by a suitable surface mounted apparatus, such as a powered walking beam 128 to operate the pumping unit 120. In another embodiment, the pumping unit 120 may comprise a Moineau or other suitable pump operable to lift fluids vertically or substantially vertically. The pumping units 120 are used to remove water and entrained coal fines from the coal seam 15 via the well bore patterns 60 and 90. Once the water is removed to the surface 14, it may be treated in gas/water separator 106 for separation of methane which may be dissolved in the water and for removal of entrained fines. After sufficient water has been removed from the coal seam 15, via gas lift, fluid pumping or other suitable manner, or pressure is otherwise lowered, coal seam gas may flow from the coal seam 15 to the surface 14 through the annulus of the first and second well bores 12 and 32 around the tubing strings and be removed via piping attached to a wellhead apparatus. The pumping unit 120 may be operated continuously or as needed to remove water drained from the coal seam 15 into the enlarged cavities 20 and 34. In a particular embodiment, gas lift is continued until the wells are kicked-off to a self- sustaining flow at which time the wells are briefly shut-in to allow replacement of the gas lift equipment with the fluid pumping equipment. The wells are then allowed to flow in self-sustaining flow subject to periodic periods of being shut-in for maintenance, lack of demand for gas and the like. After any shut-in, a well may need to be pumped for a few cycles, a few hours, days or weeks, to again initiate self- sustaining flow or other suitable production rate of gas. In a particular embodiment, the rod pumps may each produce approximately eight gallons per minute of water from a corresponding cavity 20 or 34 to the surface. A well is at self sustaining flow when the flow of gas is operable to lift any produced water such that the well may operate for an extended period of six weeks or more without pumping or artificial gas lift. Thus, the well may require periodic pumping between periods of self sustaining flow.
90098770.doc Atty. Ref. 17601-039WO1 FIGURE 5 illustrates one embodiment of the subterranean patterns 60 and 90 for accessing the coal seam 15 or other subterranean zone. The patterns 60 and 90 may be used to remove or inject water, gas or other fluids. The subterranean patterns 60 and 90 each comprises a multi-lateral pattern that has a main bore with generally symmetrically arranged and appropriately spaced laterals extending from each side of the main bore. As used herein, the term each means every one of at least a subset of the identified items. It will be understood that other suitable multi-branching or other patterns including or connected to a surface production bore may be used. For example, the patterns 60 and 90 may each comprise a single main bore. Referring to FIGURE 5, patterns 60 and 90 each include a main bore 150 extending from a corresponding cavity 20 or 34, or intersecting well bore 12 or 32, along a center of a coverage area to a distal end of the coverage area. The main bore 150 includes one or more primary lateral bores 152 extending from the main bore 150 to or at least approximately to the periphery of the coverage area. The primary lateral bores 152 may extend from opposite sides of the main bore 150. The primary lateral bores 152 may mirror each other on opposite sides of the main bore 150 or may be offset from each other along the main bore 150. Each of the primary lateral bores 152 may include a radius curving portion extending from the main bore 150 and a straight portion formed after the curved portion has reached a desired orientation. For uniform coverage, the primary lateral bores 152 may be substantially evenly spaced on each side of the main bore 150 and extend from the main bore 150 at an angle of approximately 45 degrees. The primary lateral bores 152 may shorten in length based on progression away from the corresponding cavity 20 or 34. Accordingly the distance between the cavity or intersecting well bore and the distal end of each primary lateral bore 152 through the pattern may be substantially equal for each primary lateral 152. One or more secondary lateral bores 154 may be formed off one or more of the primary lateral bores 152. In a particular embodiment, a set of secondary laterals 154 may be formed off the first primary lateral bores 152 of each pattern 60 and 90 closest to the corresponding cavity 20 and 34. The secondary laterals 154 may provide coverage in the area between the primary lateral bores 152 of patterns 60 and
90098770.doc Atty. Ref. 17601-039WO1
90. In a particular embodiment, a first primary lateral 154 may include a reversed radius section to provide more uniform coverage of the coal seam 15. The subterranean patterns 60 and 90 with their central bore and generally symmetrically arranged and appropriately spaced auxiliary bores on each side may provide a substantially uniform pattern for draining fluids from a coal seam 15 or other subterranean formation. The number and spacing of the lateral bores maybe adjusted depending on the absolute, relative and/or effective permeability of the coal seam and the size of the area covered by the pattern. The area covered by the pattern may be the area drained by the pattern, the area of a spacing unit that the pattern is designed to drain, the area within the distal points or periphery of the pattern and/or the area within the periphery of the pattern as well as the surrounding area out to a periphery intermediate to adjacent or neighboring patterns. The coverage area may also include the depth, or thickness of the coal seam or, for thick coal seams, a portion of the thickness of the seam. Thus, the pattern may include upward or downward extending branches in addition to horizontal branches. The coverage area may be a square, other quadrilateral, or other polygon, circular, oval or other ellipsoid or grid area and may be nested with other patterns of the same or similar type. It will be understood that other suitable well bore patterns may be used. As previously described, the well bore 150 and the lateral bores 152 and 154 of patterns 60 and 90 are formed by drilling through the corresponding cavity 20 or 34 using the drill string 50 and an appropriate drilling apparatus. During this operation, gamma ray logging tools and conventional MWD technologies may be employed to control the direction and orientation of the drill bit 52 so as to retain the well bore pattern within the confines of the coal seam 15 and to maintain proper spacing and orientation of the well bores 150 and 152. hi a particular embodiment, the main well bore 150 of each pattern 60 and 90 is drilled with an incline at each of a plurality of lateral branch points 156. After the main well bore 150 is complete, the drill string 50 is backed up to each successive lateral point 156 from which a primary lateral bore 152 is drilled on each side of the well bore 150. The secondary laterals 154 may be similarly formed. It will be understood that the subterranean patterns 60 and 90 may be otherwise suitably formed.
9009877Q.doc 14 Atty. Ref. 17601-039WO1 FIGURE 6 is a flow diagram illustrating a method for surface production of gas from a subterranean zone in accordance with one embodiment. In this embodiment, the subterranean zone is a coal seam and well system 10 with a pair of cavities is used to produce gas from the coal seam. It will be understood that the subterranean zone may comprise gas bearing shales and other suitable formations and that the well system 10 may have any suitable number of multi-purpose wells used to produce gas to the surface and to form bores for another producing well. Referring to FIGURE 6, the method begins after the region to be drained and the type of subterranean patterns for the region have been determined. In one embodiment, any suitable pinnate, other substantially uniform pattern providing less than ten or even five percent trapped zones in the coverage area, omni-directional or multi-branching pattern may be used to provide coverage for the region. At step 200, in an embodiment in which dual purpose wells are used, a first substantially vertical or other suitable well 12 is drilled from the surface 14 through the coal seam 15. Slant and other suitable well configurations may, for example, instead be used. In a slant well configuration, the drainage patterns may be formed off of a slant well or a slanting portion of a well with a vertical or other section at the surface. Next, at step 202, down hole logging equipment is utilized to exactly identify the location of the coal seam 15 in the first well bore 12. At step 204, the first enlarged diameter or other cavity 20 is formed in the first well bore 12 at the location of the coal seam 15. As previously discussed, the first cavity 20 may be formed by underreaming and other suitable techniques. For example, the cavity may be formed by tracing. Next, at step 206, the second substantially vertical or other suitable well 32 is drilled from the surface 14 through the coal seam 15. Slant or other suitable well configurations may instead be used. At step 208, down-hole logging equipment is utilized to exactly identify the location of the coal seam 15 in the second well bore 32. At step 210, the second enlarged diameter or other cavity 34 is formed in the second well bore 32 at the location of the coal seam 15. The second cavity 34 may be formed by any other suitable technique.
90098770.doc Atty. Ref. 17601-039WO1 Next, at step 212, the first articulated well bore 40 is drilled off the second well bore 32 to intersect the enlarged diameter cavity 20 of the first well bore 12. At step 214, the main well bore 150 for the first subterranean pattern 60 is drilled through the first articulated well bore 40 into the coal seam 15. As previously described, lateral kick-off points, or bumps may be formed along the main bore 150 during its formation to facilitate drilling of the lateral bores 152 and 154. After formation of the main well bore 150, lateral bores 152 and 154 for the subterranean pattern are drilled at step 216. At step 218, the second articulated well bore 80 is drilled off the first well bore 12 to intersect the large diameter cavity 32 of the second well bore 32. At step 220, the main well bore 150 for the second subterranean pattern 90 is drilled through the second articulated well bore 80 into the coal seam 15. As previously described, lateral kick-off points or bumps may be formed along the main bore 150 in its formation to facilitate drilling of the lateral bores 152 and 154. At step 222, lateral bores 152 and 154 for the second pattern 90 are formed. At step 224, gas lift equipment is installed in each of the first and second well bores 12 and 32 in preparation for blow-down of the bores. At step 226, compressed air is pumped down the substantially vertical well bores 12 and 32 to provide blow- down. The compressed air expands in the cavities 20 and 34, suspends the collected fluids within its volume and lifts the fluid to the surface. At the surface, air and produced methane or other gases are separated from the water and flared. The water may be disposed of as runoff, reinjected or moved to a remote site for disposal. In addition to providing gas lift, the blow-down may clean the cavities 20 and 34 and the vertical well bores 12 and 34 of debris and kick-off the well to initiate self-sustaining flow. In a particular embodiment, the blow-down may last for one, two or a few weeks. At step 228, production equipment is installed in the substantially vertical well bores 12 and 34 in place of the gas lift equipment. The production equipment may include a well head and a sucker rod pump extending down into the cavities 20 and 34 for removing water from the coal seam 15. If a well is shut in for any period of time, water builds up in the cavity 20 or 34 or self-sustaining flow is otherwise terminated,
90Q98770.doc 16 Atty. Ref. 17601-039WO1 the pump may be used to remove water and drop the pressure in the coal seam 15 to allow methane gas to continue to be diffused and to be produced up the annulus of the substantially vertical well bore. At step 230, methane gas diffused from the coal seam 15 is continuously produced at the surface 14. Methane gas may be produced in two-phase flow with the water or otherwise produced with water and/or produced after reservoir pressure has been suitably reduced. Proceeding to step 232, water that drains through the drainage patterns into the cavities that is not lifted by the produced gas is pumped to the surface with the rod pumping unit. Water may be continuously or intermittently pumped as needed for removal from the cavities 20 and 34. Next, at decisional step 234 it is determined whether the production of gas from the coal seam 15 is complete. In a particular embodiment, approximately seventy-five percent of the total gas in the coverage area of the coal seam may be produced at the completion of gas production. The production of gas may be complete after the cost of the collecting the gas exceeds the revenue generated by the well. Alternatively, gas may continue to be produced from the well until a remaining level of gas in the coal seam 15 is below required levels for mining or other operations. If production of the gas is not complete, the No branch of decisional step 234 returns to steps 230 and 232 in which gas and/or water continue to be removed from the coal seam 15. Upon completion of production, the Yes branch of decisional step 234 leads to the end of the process by which gas is produced from a coal seam. It will be understood that one or more steps may be modified, omitted, or performed in a different order. Additional steps may be added. FIGURE 7 illustrates another embodiment of the subterranean patterns 60 and 90 for accessing the coal seam 15 or other subterranean zone. As previously discussed the subterranean patterns 60 and 90 may each comprise a multi-lateral pattern that has a main bore with generally symmetrically arranged and appropriately spaced laterals extending from each side of the main bore. In the embodiment of FIGURE 7, the patterns 60 and 90 are each formed with laterals extending from the main bore before and after interception of the corresponding cavity 20 or 34.
90098770.doc 17 Atty. Ref. 17601-039WO1 Referring to FIGURE 7, patterns 60 and 90 may each include a main bore 250 extending through a corresponding cavity 20 or 34, or intersecting well bore 12 or 32, along a center of a coverage area. The main bore 250 includes one or more primary lateral bores 252 extending from the main bore 250 to or at least approximately to the periphery of the coverage area. The primary lateral bores 252 may extend from opposite sides of the main bore 250. One or more secondary lateral bores 254 may be formed off one or more of the primary lateral bores 252. hi a particular embodiment, a set of secondary lateral bores 254 may be formed off the first primary lateral bore 252 of each pattern 60 and 90. The patterns 60 and 90 may be formed with the cavities 20 and 34 between laterals 252 to achieve a desired spacing. For example, the wells 12 and 32, and thus cavities 20 and 34, may be vertical and offset a minimum well statutory spacing by forming laterals 252 and 254 between the cavities 20 and 34. As a result, in one embodiment, for example, spacing requirements may be met and/or special exemptions or permission requests avoided while still providing access to the coverage area. Although the present invention has been described with several embodiments, various changes and modifications may be suggested to one skilled in the art. It is intended that the present invention encompass such changes and modifications as fall within the scope of the appended claims and their equivalence.
9Q098770.doc 18

Claims

Atty. Ref. 17601-039WO1 WHAT IS CLAIMED IS: 1. A well system, comprising; a first well bore extending from a surface to a subterranean zone; a second well bore extending from the surface to the subterranean zone; a first articulated well bore formed off of the first well bore, the first articulated well bore intersecting the second well bore and coupled to a first pattern formed in the subterranean zone through the first articulated well bore; a second articulated well bore formed off of the second well bore, the second articulated well bore intersecting the first well bore and coupled to a second pattern formed in the subterranean zone through the second articulated well bore; the first pattern operable to transport fluids from the subterranean zone to the second well for production to the surface; and the second pattern operable to transport fluids from the subterranean zone to the first well for production to the surface. 2. The well system of Claim 1 , wherein the first and second patterns each comprise a main substantially horizontal well bore. 3. The well system of Claim 1, wherein the first and second patterns each comprise a main substantially horizontal well bore and a plurality of lateral well bores extending from the main substantially horizontal well bore. 4. The well system of Claim 1, wherein the first and second patterns each comprise a substantially horizontal pinnate pattern. 5. The well system of Claim 3, wherein, for each pattern, the distance from a distal end of each lateral well bore to the intersecting well bore through the lateral well bore and the main substantially horizontal well bore are substantially equal. 6. The well system of Claim 1, further comprising: a first cavity coupled to the first well bore and operable to collect fluids transported by the second pattern for production to the surface; and a second cavity coupled to the second well, a second cavity operable to collect fluids transported by the first pattern for production to the surface.
90098770.doc 19 Atty. Ref. 17601-039WO1 7. The well system of Claim 1, wherein the subterranean zone comprises a coal seam. 8. The well system of Claim 7, when the fluids comprise water and coal bed methane (CBM) gas. 9. The well system of Claim 1, further comprising: the first articulated well bore including a packer disposed between the first well bore and intersection of the second well bore; a second articulated well bore including a packer disposed between a second well bore and intersection of the first well bore. 10. The well system of Claim 1, wherein the first and second pattern together comprise a coverage area in the subterranean zone of at least 600 acres. 11. The well system of Claim 3, wherein a lateral of the first pattern extends from the main substantially horizontal well bore prior to intersection with the second well bore and a lateral of the second pattern extends from the main substantially horizontal well bore prior to intersection with the first well bore. 12. A well system, comprising: at least two well bores extending from a surface to a subterranean zone; each of the two well bores being used to form a substantially horizontal well bore pattern for the subterranean zone that intersects the other well bore and transports fluid from the subterranean zone to the other well bore for production to the surface; and each of the two well bores operable to collect for production to the surface fluids transported to the well bore by the substantially horizontal well bore pattern formed through the other well bore. 13. The well system of Claim 12 wherein the substantially horizontal well bore patterns each comprise a main well bore and a plurality of lateral well bores extending from the main well bore. 14. The well system of Claim 12, wherein the substantially horizontal well bore patterns each comprise a pinnate pattern.
20
90098770.doc Atty. Ref. 17601-039WO1 15. The well system of Claim 13, wherein, for each pattern, the distance from a distal end of each lateral to the intersecting well bore through the lateral well bore and the main well bore are substantially equal. 16. The well system of Claim 12, further comprising each of the two well bores including a cavity in the coal seam to collect fluids transported by a connected well bore pattern. 17. The well system of Claim 12, wherein the subterranean zone comprises a coal seam. 18. A method for forming a well system, comprising: forming a first well bore extending from a surface to a subterranean zone; forming a second well bore extending from the surface to the subterranean zone; kicking off the first well bore above the subterranean zone to form a first subterranean pattern in the subterranean zone, the first subterranean pattern coupled to the second well bore and operable to transport fluids from the subterranean zone to the second well bore for production to the surface through the second well bore; and kicking off the second well bore above the subterranean formation to form a second subterranean pattern in the subterranean formation, the second subterranean pattern coupled to the first well bore and operable to transport fluids from the subterranean zone to the first well bore for production to the surface through the first well bore. 19. The method of Claim 18, wherein at least one of the first and second subterranean patterns are formed by drilling in an under-balanced state. 20. The method of Claim 18, further comprising: forming a first cavity in the first well bore proximate to the subterranean zone; forming a second cavity in the second well bore proximate to the subterranean zone; and wherein the first subterranean pattern intersects the cavity of the second well bore and the second subterranean pattern intersects the cavity of the first well bore. 21. A method for forming a well system, comprising: forming a first well bore having a cavity proximate to a subterranean zone;
90098770.doc 21 Atty. Ref. 17601-039WO1 forming a second well bore having a cavity proximate to the subterranean zone; kicking off the first well bore above the subterranean zone to form a first pattern in the subterranean zone, the first pattern intersecting the cavity of the second 5 well bore and operable to transport fluids from the subterranean zone to the cavity of the second well bore for production to the surface through the second well bore; and kicking off the second well bore above the subterranean formation to form a second pattern in the subterranean formation, the second pattern intersecting the cavity of the first well bore and operable to transport fluids from the subterranean 10 zone to the first well bore for production to the surface through the first well bore. 22. The method of Claim 21 , further comprising initiating production in the first and second well bores by gas lift.
9Q09877Q.doc 22
EP04819050A 2003-11-17 2004-11-03 Multi-purpose well bores and method for accessing a subterranean zone from the surface Withdrawn EP1689974A1 (en)

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Families Citing this family (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8297377B2 (en) 1998-11-20 2012-10-30 Vitruvian Exploration, Llc Method and system for accessing subterranean deposits from the surface and tools therefor
US7025154B2 (en) 1998-11-20 2006-04-11 Cdx Gas, Llc Method and system for circulating fluid in a well system
US7048049B2 (en) 2001-10-30 2006-05-23 Cdx Gas, Llc Slant entry well system and method
US6280000B1 (en) 1998-11-20 2001-08-28 Joseph A. Zupanick Method for production of gas from a coal seam using intersecting well bores
US7571771B2 (en) * 2005-05-31 2009-08-11 Cdx Gas, Llc Cavity well system
US7621326B2 (en) * 2006-02-01 2009-11-24 Henry B Crichlow Petroleum extraction from hydrocarbon formations
BRPI0809527A2 (en) * 2007-03-28 2014-10-14 Shell Internationale Res Maartschappij B V METHOD FOR CONNECTING A FIRST DRILL HOLE WITH A SECOND DRILL HOLE, AND WELL HOLDING SYSTEM
EP2009231A1 (en) * 2007-06-29 2008-12-31 Shell Internationale Researchmaatschappij B.V. Method of producing crude oil
US20090090499A1 (en) * 2007-10-05 2009-04-09 Schlumberger Technology Corporation Well system and method for controlling the production of fluids
FR2944048A1 (en) * 2009-04-02 2010-10-08 Geoservices Equipements INTERVENTION DEVICE IN A FLUID OPERATING WELL, OPERATING PLANT AND ASSOCIATED METHOD
US20130037272A1 (en) * 2009-12-10 2013-02-14 Bruce A Dale Method and system for well access to subterranean formations
US9163465B2 (en) * 2009-12-10 2015-10-20 Stuart R. Keller System and method for drilling a well that extends for a large horizontal distance
CN102741500A (en) * 2009-12-15 2012-10-17 雪佛龙美国公司 System, method and assembly for wellbore maintenance operations
CN101775975A (en) * 2010-01-28 2010-07-14 郑州大学 Method for exploiting coal bed gas by hydraulic drilling and pressure relieving
AU2010344186B2 (en) * 2010-01-29 2016-04-14 Exxonmobil Upstream Research Company Temporary field storage of gas to optimize field development
US20110277992A1 (en) * 2010-05-14 2011-11-17 Paul Grimes Systems and methods for enhanced recovery of hydrocarbonaceous fluids
CN101949284A (en) * 2010-09-25 2011-01-19 北京奥瑞安能源技术开发有限公司 Coalbed methane horizontal well system and construction method thereof
CN102748014A (en) * 2011-04-19 2012-10-24 邹灵战 Quantitative predication method applicable to formation water production before drilling of gas drilling
US9388668B2 (en) * 2012-11-23 2016-07-12 Robert Francis McAnally Subterranean channel for transporting a hydrocarbon for prevention of hydrates and provision of a relief well
EP2994612B1 (en) * 2013-05-07 2023-03-15 Services Pétroliers Schlumberger Closed chamber impulse test with downhole flow rate measurement
US20150211512A1 (en) * 2014-01-29 2015-07-30 General Electric Company System and method for driving multiple pumps electrically with a single prime mover
CN104912520B (en) * 2014-03-14 2017-12-29 郑州大学 Horizontally-butted wells sluicing migration release extinction gas production method
US9777723B2 (en) 2015-01-02 2017-10-03 General Electric Company System and method for health management of pumping system
CN105672962B (en) * 2015-12-31 2018-08-10 中国石油天然气股份有限公司 A kind of air foam flow distribution device and method
CN109441404A (en) * 2018-10-31 2019-03-08 中国神华能源股份有限公司 Implement the method for the coal bed gas of underground mining multilayer coal in two main entrys
CN109630071A (en) * 2018-11-30 2019-04-16 中国神华能源股份有限公司 Coal bed gas pumping method
US10995574B2 (en) * 2019-04-24 2021-05-04 Saudi Arabian Oil Company Subterranean well thrust-propelled torpedo deployment system and method

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005012688A1 (en) * 2003-07-29 2005-02-10 Cdx Gas, Llc Method and system for accessing subterranean deposits from the surface and tools therefor

Family Cites Families (181)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US274740A (en) 1883-03-27 douglass
US54144A (en) 1866-04-24 Improved mode of boring artesian wells
US526708A (en) 1894-10-02 Well-drilling apparatus
US639036A (en) 1899-08-21 1899-12-12 Abner R Heald Expansion-drill.
US1189560A (en) 1914-10-21 1916-07-04 Georg Gondos Rotary drill.
US1285347A (en) 1918-02-09 1918-11-19 Albert Otto Reamer for oil and gas bearing sand.
US1485615A (en) 1920-12-08 1924-03-04 Arthur S Jones Oil-well reamer
US1467480A (en) 1921-12-19 1923-09-11 Petroleum Recovery Corp Well reamer
US1488106A (en) 1923-02-05 1924-03-25 Eagle Mfg Ass Intake for oil-well pumps
US1520737A (en) 1924-04-26 1924-12-30 Robert L Wright Method of increasing oil extraction from oil-bearing strata
US1777961A (en) 1927-04-04 1930-10-07 Capeliuschnicoff M Alcunovitch Bore-hole apparatus
US1674392A (en) 1927-08-06 1928-06-19 Flansburg Harold Apparatus for excavating postholes
US2018285A (en) 1934-11-27 1935-10-22 Schweitzer Reuben Richard Method of well development
US2069482A (en) 1935-04-18 1937-02-02 James I Seay Well reamer
US2150228A (en) 1936-08-31 1939-03-14 Luther F Lamb Packer
US2169718A (en) 1937-04-01 1939-08-15 Sprengund Tauchgesellschaft M Hydraulic earth-boring apparatus
US2335085A (en) 1941-03-18 1943-11-23 Colonnade Company Valve construction
US2490350A (en) 1943-12-15 1949-12-06 Claude C Taylor Means for centralizing casing and the like in a well
US2450223A (en) 1944-11-25 1948-09-28 William R Barbour Well reaming apparatus
US2679903A (en) 1949-11-23 1954-06-01 Sid W Richardson Inc Means for installing and removing flow valves or the like
US2726847A (en) 1952-03-31 1955-12-13 Oilwell Drain Hole Drilling Co Drain hole drilling equipment
US2726063A (en) 1952-05-10 1955-12-06 Exxon Research Engineering Co Method of drilling wells
US2847189A (en) 1953-01-08 1958-08-12 Texas Co Apparatus for reaming holes drilled in the earth
US2797893A (en) 1954-09-13 1957-07-02 Oilwell Drain Hole Drilling Co Drilling and lining of drain holes
US2783018A (en) 1955-02-11 1957-02-26 Vac U Lift Company Valve means for suction lifting devices
US2934904A (en) 1955-09-01 1960-05-03 Phillips Petroleum Co Dual storage caverns
US2911008A (en) 1956-04-09 1959-11-03 Manning Maxwell & Moore Inc Fluid flow control device
US2980142A (en) 1958-09-08 1961-04-18 Turak Anthony Plural dispensing valve
US3208537A (en) 1960-12-08 1965-09-28 Reed Roller Bit Co Method of drilling
US3163211A (en) 1961-06-05 1964-12-29 Pan American Petroleum Corp Method of conducting reservoir pilot tests with a single well
US3385382A (en) 1964-07-08 1968-05-28 Otis Eng Co Method and apparatus for transporting fluids
US3347595A (en) 1965-05-03 1967-10-17 Pittsburgh Plate Glass Co Establishing communication between bore holes in solution mining
FR1533221A (en) 1967-01-06 1968-07-19 Dba Sa Digitally Controlled Flow Valve
US3443648A (en) 1967-09-13 1969-05-13 Fenix & Scisson Inc Earth formation underreamer
US3534822A (en) 1967-10-02 1970-10-20 Walker Neer Mfg Co Well circulating device
US3809519A (en) 1967-12-15 1974-05-07 Ici Ltd Injection moulding machines
US3578077A (en) 1968-05-27 1971-05-11 Mobil Oil Corp Flow control system and method
US3503377A (en) 1968-07-30 1970-03-31 Gen Motors Corp Control valve
US3528516A (en) 1968-08-21 1970-09-15 Cicero C Brown Expansible underreamer for drilling large diameter earth bores
US3530675A (en) 1968-08-26 1970-09-29 Lee A Turzillo Method and means for stabilizing structural layer overlying earth materials in situ
US3582138A (en) 1969-04-24 1971-06-01 Robert L Loofbourow Toroid excavation system
US3587743A (en) 1970-03-17 1971-06-28 Pan American Petroleum Corp Explosively fracturing formations in wells
US3684041A (en) 1970-11-16 1972-08-15 Baker Oil Tools Inc Expansible rotary drill bit
US3692041A (en) 1971-01-04 1972-09-19 Gen Electric Variable flow distributor
FI46651C (en) 1971-01-22 1973-05-08 Rinta Ways to drive water-soluble liquids and gases to a small extent.
US3744565A (en) 1971-01-22 1973-07-10 Cities Service Oil Co Apparatus and process for the solution and heating of sulfur containing natural gas
US3757876A (en) 1971-09-01 1973-09-11 Smith International Drilling and belling apparatus
US3757877A (en) 1971-12-30 1973-09-11 Grant Oil Tool Co Large diameter hole opener for earth boring
US3828867A (en) 1972-05-15 1974-08-13 A Elwood Low frequency drill bit apparatus and method of locating the position of the drill head below the surface of the earth
US3902322A (en) 1972-08-29 1975-09-02 Hikoitsu Watanabe Drain pipes for preventing landslides and method for driving the same
US3800830A (en) 1973-01-11 1974-04-02 B Etter Metering valve
US3825081A (en) 1973-03-08 1974-07-23 H Mcmahon Apparatus for slant hole directional drilling
US3874413A (en) 1973-04-09 1975-04-01 Vals Construction Multiported valve
US3907045A (en) 1973-11-30 1975-09-23 Continental Oil Co Guidance system for a horizontal drilling apparatus
US3887008A (en) 1974-03-21 1975-06-03 Charles L Canfield Downhole gas compression technique
US4022279A (en) 1974-07-09 1977-05-10 Driver W B Formation conditioning process and system
US3934649A (en) 1974-07-25 1976-01-27 The United States Of America As Represented By The United States Energy Research And Development Administration Method for removal of methane from coalbeds
US3957082A (en) 1974-09-26 1976-05-18 Arbrook, Inc. Six-way stopcock
US3961824A (en) 1974-10-21 1976-06-08 Wouter Hugo Van Eek Method and system for winning minerals
SE386500B (en) 1974-11-25 1976-08-09 Sjumek Sjukvardsmek Hb GAS MIXTURE VALVE
US4037658A (en) 1975-10-30 1977-07-26 Chevron Research Company Method of recovering viscous petroleum from an underground formation
US4020901A (en) 1976-01-19 1977-05-03 Chevron Research Company Arrangement for recovering viscous petroleum from thick tar sand
US4030310A (en) 1976-03-04 1977-06-21 Sea-Log Corporation Monopod drilling platform with directional drilling
US4073351A (en) 1976-06-10 1978-02-14 Pei, Inc. Burners for flame jet drill
US4060130A (en) 1976-06-28 1977-11-29 Texaco Trinidad, Inc. Cleanout procedure for well with low bottom hole pressure
JPS5358105A (en) 1976-11-08 1978-05-25 Nippon Concrete Ind Co Ltd Method of generating supporting force for middle excavation system
US4089374A (en) 1976-12-16 1978-05-16 In Situ Technology, Inc. Producing methane from coal in situ
US4136996A (en) 1977-05-23 1979-01-30 Texaco Development Corporation Directional drilling marine structure
US4134463A (en) 1977-06-22 1979-01-16 Smith International, Inc. Air lift system for large diameter borehole drilling
US4169510A (en) 1977-08-16 1979-10-02 Phillips Petroleum Company Drilling and belling apparatus
US4151880A (en) 1977-10-17 1979-05-01 Peabody Vann Vent assembly
NL7713455A (en) 1977-12-06 1979-06-08 Stamicarbon PROCEDURE FOR EXTRACTING CABBAGE IN SITU.
US4156437A (en) 1978-02-21 1979-05-29 The Perkin-Elmer Corporation Computer controllable multi-port valve
US4182423A (en) 1978-03-02 1980-01-08 Burton/Hawks Inc. Whipstock and method for directional well drilling
US4226475A (en) 1978-04-19 1980-10-07 Frosch Robert A Underground mineral extraction
NL7806559A (en) 1978-06-19 1979-12-21 Stamicarbon DEVICE FOR MINERAL EXTRACTION THROUGH A BOREHOLE.
US4221433A (en) 1978-07-20 1980-09-09 Occidental Minerals Corporation Retrogressively in-situ ore body chemical mining system and method
US4257650A (en) 1978-09-07 1981-03-24 Barber Heavy Oil Process, Inc. Method for recovering subsurface earth substances
US4189184A (en) 1978-10-13 1980-02-19 Green Harold F Rotary drilling and extracting process
US4224989A (en) 1978-10-30 1980-09-30 Mobil Oil Corporation Method of dynamically killing a well blowout
US4366988A (en) 1979-02-16 1983-01-04 Bodine Albert G Sonic apparatus and method for slurry well bore mining and production
US4283088A (en) 1979-05-14 1981-08-11 Tabakov Vladimir P Thermal--mining method of oil production
US4296785A (en) 1979-07-09 1981-10-27 Mallinckrodt, Inc. System for generating and containerizing radioisotopes
US4222611A (en) 1979-08-16 1980-09-16 United States Of America As Represented By The Secretary Of The Interior In-situ leach mining method using branched single well for input and output
US4312377A (en) 1979-08-29 1982-01-26 Teledyne Adams, A Division Of Teledyne Isotopes, Inc. Tubular valve device and method of assembly
CA1140457A (en) 1979-10-19 1983-02-01 Noval Technologies Ltd. Method for recovering methane from coal seams
US4333539A (en) 1979-12-31 1982-06-08 Lyons William C Method for extended straight line drilling from a curved borehole
US4386665A (en) 1980-01-14 1983-06-07 Mobil Oil Corporation Drilling technique for providing multiple-pass penetration of a mineral-bearing formation
US4299295A (en) 1980-02-08 1981-11-10 Kerr-Mcgee Coal Corporation Process for degasification of subterranean mineral deposits
US4303127A (en) 1980-02-11 1981-12-01 Gulf Research & Development Company Multistage clean-up of product gas from underground coal gasification
US4317492A (en) 1980-02-26 1982-03-02 The Curators Of The University Of Missouri Method and apparatus for drilling horizontal holes in geological structures from a vertical bore
US4328577A (en) 1980-06-03 1982-05-04 Rockwell International Corporation Muldem automatically adjusting to system expansion and contraction
US4372398A (en) 1980-11-04 1983-02-08 Cornell Research Foundation, Inc. Method of determining the location of a deep-well casing by magnetic field sensing
JPS627747Y2 (en) 1981-03-17 1987-02-23
US4390067A (en) 1981-04-06 1983-06-28 Exxon Production Research Co. Method of treating reservoirs containing very viscous crude oil or bitumen
US4396076A (en) 1981-04-27 1983-08-02 Hachiro Inoue Under-reaming pile bore excavator
US4433182A (en) * 1981-04-30 1984-02-21 Fmc Corporation Insecticidal 2,2'-bridged[1,1'-biphenyl]-3-ylmethyl esters
US4397360A (en) 1981-07-06 1983-08-09 Atlantic Richfield Company Method for forming drain holes from a cased well
US4415205A (en) 1981-07-10 1983-11-15 Rehm William A Triple branch completion with separate drilling and completion templates
US4437706A (en) * 1981-08-03 1984-03-20 Gulf Canada Limited Hydraulic mining of tar sands with submerged jet erosion
US4401171A (en) 1981-12-10 1983-08-30 Dresser Industries, Inc. Underreamer with debris flushing flow path
US4442896A (en) * 1982-07-21 1984-04-17 Reale Lucio V Treatment of underground beds
US4463988A (en) * 1982-09-07 1984-08-07 Cities Service Co. Horizontal heated plane process
FR2545006B1 (en) * 1983-04-27 1985-08-16 Mancel Patrick DEVICE FOR SPRAYING PRODUCTS, ESPECIALLY PAINTS
US4502733A (en) * 1983-06-08 1985-03-05 Tetra Systems, Inc. Oil mining configuration
US4512422A (en) * 1983-06-28 1985-04-23 Rondel Knisley Apparatus for drilling oil and gas wells and a torque arrestor associated therewith
US4494616A (en) * 1983-07-18 1985-01-22 Mckee George B Apparatus and methods for the aeration of cesspools
FR2551491B1 (en) * 1983-08-31 1986-02-28 Elf Aquitaine MULTIDRAIN OIL DRILLING AND PRODUCTION DEVICE
US4565252A (en) * 1984-03-08 1986-01-21 Lor, Inc. Borehole operating tool with fluid circulation through arms
US4646836A (en) * 1984-08-03 1987-03-03 Hydril Company Tertiary recovery method using inverted deviated holes
US4651836A (en) * 1986-04-01 1987-03-24 Methane Drainage Ventures Process for recovering methane gas from subterranean coalseams
US4662440A (en) * 1986-06-20 1987-05-05 Conoco Inc. Methods for obtaining well-to-well flow communication
US4754808A (en) * 1986-06-20 1988-07-05 Conoco Inc. Methods for obtaining well-to-well flow communication
US4727937A (en) * 1986-10-02 1988-03-01 Texaco Inc. Steamflood process employing horizontal and vertical wells
US4718485A (en) * 1986-10-02 1988-01-12 Texaco Inc. Patterns having horizontal and vertical wells
US4889199A (en) * 1987-05-27 1989-12-26 Lee Paul B Downhole valve for use when drilling an oil or gas well
CA2009782A1 (en) * 1990-02-12 1991-08-12 Anoosh I. Kiamanesh In-situ tuned microwave oil extraction process
NL9000426A (en) * 1990-02-22 1991-09-16 Maria Johanna Francien Voskamp METHOD AND SYSTEM FOR UNDERGROUND GASIFICATION OF STONE OR BROWN.
US5194859A (en) * 1990-06-15 1993-03-16 Amoco Corporation Apparatus and method for positioning a tool in a deviated section of a borehole
US5197783A (en) * 1991-04-29 1993-03-30 Esso Resources Canada Ltd. Extendable/erectable arm assembly and method of borehole mining
US5193620A (en) * 1991-08-05 1993-03-16 Tiw Corporation Whipstock setting method and apparatus
US5197553A (en) * 1991-08-14 1993-03-30 Atlantic Richfield Company Drilling with casing and retrievable drill bit
US5199496A (en) * 1991-10-18 1993-04-06 Texaco, Inc. Subsea pumping device incorporating a wellhead aspirator
US5201817A (en) * 1991-12-27 1993-04-13 Hailey Charles D Downhole cutting tool
US5289888A (en) * 1992-05-26 1994-03-01 Rrkt Company Water well completion method
US5301760C1 (en) * 1992-09-10 2002-06-11 Natural Reserve Group Inc Completing horizontal drain holes from a vertical well
US5485089A (en) * 1992-11-06 1996-01-16 Vector Magnetics, Inc. Method and apparatus for measuring distance and direction by movable magnetic field source
US5402851A (en) * 1993-05-03 1995-04-04 Baiton; Nick Horizontal drilling method for hydrocarbon recovery
US5394950A (en) * 1993-05-21 1995-03-07 Gardes; Robert A. Method of drilling multiple radial wells using multiple string downhole orientation
US5727629A (en) * 1996-01-24 1998-03-17 Weatherford/Lamb, Inc. Wellbore milling guide and method
US6209636B1 (en) * 1993-09-10 2001-04-03 Weatherford/Lamb, Inc. Wellbore primary barrier and related systems
US5385205A (en) * 1993-10-04 1995-01-31 Hailey; Charles D. Dual mode rotary cutting tool
US5494121A (en) * 1994-04-28 1996-02-27 Nackerud; Alan L. Cavern well completion method and apparatus
US5564503A (en) * 1994-08-26 1996-10-15 Halliburton Company Methods and systems for subterranean multilateral well drilling and completion
US5501273A (en) * 1994-10-04 1996-03-26 Amoco Corporation Method for determining the reservoir properties of a solid carbonaceous subterranean formation
US5540282A (en) * 1994-10-21 1996-07-30 Dallas; L. Murray Apparatus and method for completing/recompleting production wells
US5613242A (en) * 1994-12-06 1997-03-18 Oddo; John E. Method and system for disposing of radioactive solid waste
US5501279A (en) * 1995-01-12 1996-03-26 Amoco Corporation Apparatus and method for removing production-inhibiting liquid from a wellbore
US5732776A (en) * 1995-02-09 1998-03-31 Baker Hughes Incorporated Downhole production well control system and method
US5868210A (en) * 1995-03-27 1999-02-09 Baker Hughes Incorporated Multi-lateral wellbore systems and methods for forming same
US5706871A (en) * 1995-08-15 1998-01-13 Dresser Industries, Inc. Fluid control apparatus and method
US6457540B2 (en) * 1996-02-01 2002-10-01 Robert Gardes Method and system for hydraulic friction controlled drilling and completing geopressured wells utilizing concentric drill strings
US5720356A (en) * 1996-02-01 1998-02-24 Gardes; Robert Method and system for drilling underbalanced radial wells utilizing a dual string technique in a live well
US5944107A (en) * 1996-03-11 1999-08-31 Schlumberger Technology Corporation Method and apparatus for establishing branch wells at a node of a parent well
US6056059A (en) * 1996-03-11 2000-05-02 Schlumberger Technology Corporation Apparatus and method for establishing branch wells from a parent well
US6547006B1 (en) * 1996-05-02 2003-04-15 Weatherford/Lamb, Inc. Wellbore liner system
WO1998009049A1 (en) * 1996-08-30 1998-03-05 Camco International, Inc. Method and apparatus to seal a junction between a lateral and a main wellbore
US6012520A (en) * 1996-10-11 2000-01-11 Yu; Andrew Hydrocarbon recovery methods by creating high-permeability webs
US5879057A (en) * 1996-11-12 1999-03-09 Amvest Corporation Horizontal remote mining system, and method
US5863283A (en) * 1997-02-10 1999-01-26 Gardes; Robert System and process for disposing of nuclear and other hazardous wastes in boreholes
US5884704A (en) * 1997-02-13 1999-03-23 Halliburton Energy Services, Inc. Methods of completing a subterranean well and associated apparatus
US6019173A (en) * 1997-04-04 2000-02-01 Dresser Industries, Inc. Multilateral whipstock and tools for installing and retrieving
US6030048A (en) * 1997-05-07 2000-02-29 Tarim Associates For Scientific Mineral And Oil Exploration Ag. In-situ chemical reactor for recovery of metals or purification of salts
US20020043404A1 (en) * 1997-06-06 2002-04-18 Robert Trueman Erectable arm assembly for use in boreholes
US5868202A (en) * 1997-09-22 1999-02-09 Tarim Associates For Scientific Mineral And Oil Exploration Ag Hydrologic cells for recovery of hydrocarbons or thermal energy from coal, oil-shale, tar-sands and oil-bearing formations
US6050335A (en) * 1997-10-31 2000-04-18 Shell Oil Company In-situ production of bitumen
US6024171A (en) * 1998-03-12 2000-02-15 Vastar Resources, Inc. Method for stimulating a wellbore penetrating a solid carbonaceous subterranean formation
GB9810722D0 (en) * 1998-05-20 1998-07-15 Johnston Sidney Method
US6263965B1 (en) * 1998-05-27 2001-07-24 Tecmark International Multiple drain method for recovering oil from tar sand
US6135208A (en) * 1998-05-28 2000-10-24 Halliburton Energy Services, Inc. Expandable wellbore junction
US6179054B1 (en) * 1998-07-31 2001-01-30 Robert G Stewart Down hole gas separator
GB2342670B (en) * 1998-09-28 2003-03-26 Camco Int High gas/liquid ratio electric submergible pumping system utilizing a jet pump
US6280000B1 (en) * 1998-11-20 2001-08-28 Joseph A. Zupanick Method for production of gas from a coal seam using intersecting well bores
US6681855B2 (en) * 2001-10-19 2004-01-27 Cdx Gas, L.L.C. Method and system for management of by-products from subterranean zones
US6454000B1 (en) * 1999-11-19 2002-09-24 Cdx Gas, Llc Cavity well positioning system and method
US6662870B1 (en) * 2001-01-30 2003-12-16 Cdx Gas, L.L.C. Method and system for accessing subterranean deposits from a limited surface area
US7025154B2 (en) * 1998-11-20 2006-04-11 Cdx Gas, Llc Method and system for circulating fluid in a well system
US6425448B1 (en) * 2001-01-30 2002-07-30 Cdx Gas, L.L.P. Method and system for accessing subterranean zones from a limited surface area
US6679322B1 (en) * 1998-11-20 2004-01-20 Cdx Gas, Llc Method and system for accessing subterranean deposits from the surface
US6199633B1 (en) * 1999-08-27 2001-03-13 James R. Longbottom Method and apparatus for intersecting downhole wellbore casings
US6561277B2 (en) * 2000-10-13 2003-05-13 Schlumberger Technology Corporation Flow control in multilateral wells
WO2002034931A2 (en) * 2000-10-26 2002-05-02 Guyer Joe E Method of generating and recovering gas from subsurface formations of coal, carbonaceous shale and organic-rich shales
US6962030B2 (en) * 2001-10-04 2005-11-08 Pd International Services, Inc. Method and apparatus for interconnected, rolling rig and oilfield building(s)
US6722452B1 (en) * 2002-02-19 2004-04-20 Cdx Gas, Llc Pantograph underreamer
US6968893B2 (en) * 2002-04-03 2005-11-29 Target Drilling Inc. Method and system for production of gas and water from a gas bearing strata during drilling and after drilling completion
US7360595B2 (en) * 2002-05-08 2008-04-22 Cdx Gas, Llc Method and system for underground treatment of materials
US6991047B2 (en) * 2002-07-12 2006-01-31 Cdx Gas, Llc Wellbore sealing system and method
US6991048B2 (en) * 2002-07-12 2006-01-31 Cdx Gas, Llc Wellbore plug system and method
US6976547B2 (en) * 2002-07-16 2005-12-20 Cdx Gas, Llc Actuator underreamer
US6860147B2 (en) * 2002-09-30 2005-03-01 Alberta Research Council Inc. Process for predicting porosity and permeability of a coal bed
US7222670B2 (en) * 2004-02-27 2007-05-29 Cdx Gas, Llc System and method for multiple wells from a common surface location

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005012688A1 (en) * 2003-07-29 2005-02-10 Cdx Gas, Llc Method and system for accessing subterranean deposits from the surface and tools therefor

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of WO2005049964A1 *

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